FLATNESS OF PLANE SURFACES
Where the surfaces intended to be exposed in the finished cast stone are declared by the cast stone manufacturer to be plane, they shall not deviate from a plane by more than the values given below.
Max permitted variation = 0.3% of the maximum dimension of the item or 2 mm, whichever is the greater.
The equipment required to perform this test shall be:
- Straight edge of equal or greater length to the maximum dimension over which the flatness is to be measured or 1.5 m whichever is the lesser.
- Feeler gauges (two sets).